Bo's Currency Converter - Python 3.3.4

# Python 3 version of Bo Milanovich's Currency Converter Python/Qt tutorial (https://www.youtube.com/watch?v=8D_aEYiBU2c)
import sys
import urllib.request
import csv
import codecs
from PySide.QtCore import *
from PySide.QtGui import *


class Form(QDialog):
    def __init__(self, parent=None):
        super(Form,self).__init__(parent)

        # I had to move this from the 'getdate' function to the __init__. Otherwise got error:
        #  AttributeError: 'Form' object has no attribute 'rates'
        self.rates = {}

        # Has to be 'getdate()', not 'getdate' otherwise it returns the object reference, like this:
        # <bound method Form.getdate of <__main__.Form object at 0x0000000004026BC8>>.
        #
        # This results in the following error when trying to initialize the QLabel widget below:
        #   TypeError: 'PySide.QtGui.QLabel' called with wrong argument types:
        #      PySide.QtGui.QLabel(method)
        date = self.getdate

        rates = sorted(self.rates.keys())
        dateLabel = QLabel(date)
        self.fromComboBox = QComboBox()
        self.fromComboBox.addItems(rates)
        self.fromSpinBox = QDoubleSpinBox() # Takes Double data type, not just integers.
        self.fromSpinBox.setRange(0.01,10000000.00) # Ranges allowed for spinbox
        self.fromSpinBox.setValue(1.00) # Default value
        self.toComboBox = QComboBox()
        self.toComboBox.addItems(rates)
        self.toLabel = QLabel("1.00") # Default value

        grid = QGridLayout() # Instead of vertical layout QVBoxLayout()

        # Works like the Tkinter grid geometry manager!
        grid.addWidget(dateLabel, 0, 0) # row,column
        grid.addWidget(self.fromComboBox, 1, 0)
        grid.addWidget(self.fromSpinBox, 1, 1)
        grid.addWidget(self.toComboBox, 2, 0)
        grid.addWidget(self.toLabel, 2, 1)
        self.setLayout(grid)

        # The signal currentIndexChanged is emitted when the selected item in a combo box changes.
        self.connect(self.fromComboBox, SIGNAL("currentIndexChanged(int)"), self.updateUi)
        self.connect(self.toComboBox, SIGNAL("currentIndexChanged(int)"), self.updateUi)

        # The signal valueChanged is emitted when the value in the spinbox changes.
        self.connect(self.fromSpinBox, SIGNAL("valueChanged(double)"), self.updateUi)

    def updateUi(self):
        to = self.toComboBox.currentText()
        from_ = self.fromComboBox.currentText() # Underscore is used because 'from' is a reserved word in Python.

        amount = (self.rates[from_] / self.rates[to]) * self.fromSpinBox.value()
        self.toLabel.setText("%0.2f" % amount)

    def getdate(self):
        try:
            date = "Unknown"
            url = "http://www.bankofcanada.ca/en/markets/csv/exchange_eng.csv"
            httpstream = urllib.request.urlopen(url)

            # Because urllib returns bytes, they have to be decoded.
            fh = csv.reader(codecs.iterdecode(httpstream, 'utf-8'))

            # fh is already a list, so we don't have to use 'rstrip' or 'split'
            for line in fh:

                if not line or line[0].startswith("#"):
                    continue

                if line[0].startswith('Date'):
                    # The 'Date' line contains several dates in ascending order from left to right.
                    # This grabs the right most date which is the most recent.
                    date = line[8]
                else:
                    try:
                        # The value at position 8 in the currency lines correspond to the most recent date.
                        value = float(line[8])
                        self.rates[line[0]] = value
                    except ValueError:
                        pass
            return "Exchange rates date: " + date

        except Exception as e:
            return "Failed to download:\n%s" % e

app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()